The invention pertains to monitoring systems. More particularly, the invention pertains to such systems which are capable of outputting synchronized audible or visible indicia indicative of the presence of an alarm condition.
A variety of alarm systems for monitoring various ambient conditions in regions of interest are known. These systems, which include fire detection, gas detection or intrusion detection devices, often incorporate ancillary output devices such as horns or speakers or piezoelectric tone generating devices to produce various types of condition indicating audible outputs. Visible outputs which produce various pulsed light patterns are also known.
Advantages of standardized audible alarm signals have been recognized. One known standardized alarm signal with a predetermined temporal pattern has been defined by American National Standard Institute S3.41. It is also been recognized that various foreign jurisdictions might specify a different standard.
Beyond publicly issued standards, it has been recognized that there are advantages to synchronizing the various audible and visible outputs. One known synchronizing approach is disclosed and claimed in U.S. Pat. 5,850,178 entitled xe2x80x9cAlarm System having Synchronizing Pulse Generator and Synchronizing Pulse Missing Detectorxe2x80x9d assigned to the assignee hereof and incorporated herein by reference. While known synchronization approaches and methods have been found to be useful, there continues to be a need for synchronization systems and methods which respond to evolving needs.
An electrical device usable in a multiple device communication system incorporates control circuitry for receiving and analyzing received signal patterns. In response to a received predetermined signal pattern, a synchronized output is generated. In one aspect, the output can be produced by a transducer. Exemplary transducers include audible output devices and visual output devices.
In yet another aspect of the invention, the unit includes discrimination circuitry which initially recognizes that a predetermined pattern has been received and which energizes an output transducer in accordance with subsequently received predetermined patterns. In this embodiment, the output transducer will continue to be driven, in synchronism with the received patterns until the incoming patterns cease.
The output transducer can be driven to produce a pattern identical to a received pattern. Alternately, the synchronized output can be provided in the form of a different pattern.
In another aspect, the control circuitry incorporates a programmed processor and associated pre-stored executable instructions along with at least one pre-stored output pattern. Upon receipt of an incoming pattern which is substantially similar to the pre-stored output pattern, the processor in turn causes the output transducer, which could be audible or visible, to emit a synchronized pattern. As noted above, the synchronized pattern can be identical to the. received pattern. Alternately, it can be synchronized to the received pattern but distinguishable therefrom.
The electrical unit can in turn generate at a selected output port an output pre-determined synchronizing pattern to be coupled to other electrical units. In such an event, the coupled output synchronizing pattern from the first unit causes the subsequent units to emit a synchronized audible and/or visible output signal corresponding to the received signal. Alternately, the audible and/or observable output signals can be synchronized with a received input pattern but can be distinguishable therefrom.
In one embodiment, an electrical unit which has recognized the presence of a predetermined condition, such as fire, gas or intrusion, can enter a state indicative thereof. That unit can in turn output a synchronizing pattern to units coupled thereto. In response to receipt of the synchronizing pattern, those units can emit a synchronized audible/visible output either substantially identical thereto or synchronized therewith but distinguishable therefrom.
In another embodiment, a common control element can be coupled to the various electrical units. The synchronizing audible/visible signal can be originated by the common control element in response to detection of an alarm condition.
The synchronizing signal can in turn be coupled to a plurality of electrical units in the system either directly or in daisy-chain fashion by causing the units to emit a signal corresponding to the received synchronization signal from the panel. The emitted signal is received by other electrical units in the system causing same to output a synchronized audible/visible indicia.
In yet another embodiment, a signal discrimination module can be coupled to the control element. This module can in turn detect the presence of a synchronizing output-signal from the control element. It can in turn couple that signal to a plurality of electrical units which do not incorporate the above noted discrimination circuitry.
Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings.